1. Field of the Invention
The present invention relates to an infrared emitter, and, more particularly to an infrared emitter embodied as a planar emitter.
2. Description of the Related Art
Infrared emitters embodied as planar emitters are used in dryer systems which are used to dry web materials, for example paper or board webs. Depending on the width of the web to be dried and the desired heating output, the requisite number of emitters are assembled with aligned emission surfaces to form a drying unit.
The basic structure of a single generic infrared emitter is illustrated in FIG. 16 and described, for example, in DE 199 01 145-A1.
The fuel/air mixture needed for the operation of the emitter is supplied to the emitter through an opening (a) in the housing (b) and firstly passes into a distribution chamber (c), in which the mixture is distributed uniformly over the emitter surface, at right angles to the view shown here. The gases then pass through a barrier (d) which is configured so as to be permeable. The main task of the barrier (d) is to isolate the combustion chamber (e), in which the gas is burned, from the distribution chamber (c), in which the unburned gas mixture is located, in such a way that no flashback from the combustion chamber (e) to the distribution chamber (c) can take place. In addition, the barrier (d) should expediently be designed such that the best possible heat transfer from the hot combustion waste gases to the solid element that emits the radiation, that is to say the surface of the barrier (d) itself or possibly the walls of the combustion chamber (e) and the actual radiant element (f) is prepared. The geometric/constructional configuration of combustion chamber (e) and radiant element (f) is likewise carried out from the following points of view:                optimized heat transfer,        maximized heat emission,        
minimum heat losses to the side and in the direction of the distribution chamber, taking into account thermal expansion which occurs and application specific special features, such as possible contamination, thermal shock which occurs, and so on.
What is needed in the art is an improved construction that increases the lifetime of the emitter.